Traditional signal amplitude detection circuit usually detects signal amplitudes by a way of using analog circuit filtering or analog signal amplitude-energy conversion, namely by a way of using analog circuits to realize the detection for the signal amplitude mainly. However, the detection result of the analog circuits may have an error due to some factors in technological process, and the bandwidth of analog filters and working point of the analog signal amplitude-energy conversion circuit cannot be determined accurately; moreover, no matter whether the analog filter or the analog signal amplitude-energy conversion circuit is used, it's necessary to add an extra A-D conversion circuit if the signal amplitude undergoes a detection by a following digital circuit, which brings a complicated structure for the whole signal amplitude detection circuit, thereby resulting in a difficult implementation.
Therefore, there is a need to provide an improved signal amplitude detection circuit to overcome above drawbacks.